6i6 Microscopic Organisms in Blood of Man and Animals. [part hi. 



It seems somewhat strange that, notwithstanding the marked prevalence of 

 embryo-hsematozoa, the Filaria immitis has not, so far as I can learn, been recognised 

 in India. I have often searched specially for it, but in vain. The only mature parasite 

 which appears to affect the circulatory system of dogs in this country is the Filaria 

 saTiguinolenta, a description of which, together with an account of the pathological 

 changes which are caused by it during its development in the walls of the aorta and 

 adjacent tissues, was published by me in 1874.* This Filaria may be readily recognised 

 by its pink hue, when fresh, and by many other characters which need not be specially 

 referred to on this occasion. It does not appear to be viviparous, for, although living 

 Filaria may readily be pressed out of mature ova, I have never found free embryos 

 either in the body of the female parasite, or in the fluid contained in the pouch in 

 which it is usually lodged, although an abundance of free ova are always present. 

 Notwithstanding the circumstance that this is the only mature helminth which I 

 have found associated with the embryo-hgematozoa in India, I cannot believe that 

 there is a genetic connection between them, for it frequently happens that the mature 

 worm may be present in abundance unassociated with blood embryos of any kind, and 

 sometimes it is found that the latter exists without any trace of the former. 



Recently a very interesting observation bearing on this subject has been made 

 by Ercolani — an observation which may serve at some future period to throw some 

 light as to the origin of the microzoa of dogs in this country.! Ercolani has, on two 

 occasions, found sexually mature worms in the subcutaneous cellular tissue of dogs 

 in Italy. In one of the cases they were very numerous and were associated with 

 embryos in the blood. The writer suggests that possibly still other mature parasites 

 may eventually be discovered, as the embryos in the blood are probably not derived 

 from the same species. I have, on several occasions, endeavoured to find the mature 

 form in the cellular tissues of various parts of the body of dogs, but have not been 

 successful. This, however, by no means implies that such thread-like creatures were 

 not present. 



C— Nematoid Hsematozoa of Man. 

 There remain now to be considered the nematoid hrematozoa which have been 

 found in the circulation of man. The literature of this subject dates from the period 

 of the publication in 1872 of a paper submitted by myself to the Grovernment, entitled 

 " On a Hsematozoon in Human Blood." | Towards the beginning of July of that year, 

 I found nine minute nematoid worms in a state of great activity on a slide containing a 

 drop of blood from the finger of a Hindoo. They were about // in length, and ijsVtj" in 

 width, or slightly less than the average diameter of a human red blood-corpuscle (-3 mm. 

 X -007 mm.). 



* Loc. cit. , page 503 of this volume. 



f A notice by Paul Giiterbock in Virchow and Hirsch's Jahresiericht for 1875, vol. i, p. 379. 

 % Eighth Annual Report of the Sanitary Commissioner with the Government of India, 1872. Also India it 

 AnnaU of Medical Science, vol. xvi, and page 603 of this volume. 



